// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_MESSAGE_CENTER_MESSAGE_CENTER_H_
#define UI_MESSAGE_CENTER_MESSAGE_CENTER_H_

#include <stddef.h>

#include <string>

#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "ui/message_center/message_center_export.h"
#include "ui/message_center/message_center_types.h"
#include "ui/message_center/notification_list.h"

class DownloadNotification;
class DownloadNotificationTestBase;

namespace base {
class DictionaryValue;
}

// Interface to manage the NotificationList. The client (e.g. Chrome) calls
// [Add|Remove|Update]Notification to create and update notifications in the
// list. It also sends those changes to its observers when a notification
// is shown, closed, or clicked on.
//
// MessageCenter is agnostic of profiles; it uses the string returned by
// message_center::Notification::id() to uniquely identify a notification. It is
// the caller's responsibility to formulate the id so that 2 different
// notification should have different ids. For example, if the caller supports
// multiple profiles, then caller should encode both profile characteristics and
// notification front end's notification id into a new id and set it into the
// notification instance before passing that in. Consequently the id passed to
// observers will be this unique id, which can be used with MessageCenter
// interface but probably not higher level interfaces.

namespace message_center {

namespace test {
    class MessagePopupCollectionTest;
}

class MessageCenterObserver;
class MessageCenterImplTest;
class NotificationBlocker;
class NotifierSettingsProvider;

class MESSAGE_CENTER_EXPORT MessageCenter {
public:
    // Creates the global message center object.
    static void Initialize();

    // Returns the global message center object. Returns NULL if Initialize is not
    // called.
    static MessageCenter* Get();

    // Destroys the global message_center object.
    static void Shutdown();

    // Management of the observer list.
    virtual void AddObserver(MessageCenterObserver* observer) = 0;
    virtual void RemoveObserver(MessageCenterObserver* observer) = 0;

    // Queries of current notification list status.
    virtual size_t NotificationCount() const = 0;
    virtual size_t UnreadNotificationCount() const = 0;
    virtual bool HasPopupNotifications() const = 0;
    virtual bool IsQuietMode() const = 0;
    virtual bool HasClickedListener(const std::string& id) = 0;

    // Find the notification with the corresponding id. Returns NULL if not found.
    // The returned instance is owned by the message center.
    virtual message_center::Notification* FindVisibleNotificationById(
        const std::string& id)
        = 0;

    // Gets all notifications to be shown to the user in the message center.  Note
    // that queued changes due to the message center being open are not reflected
    // in this list.
    virtual const NotificationList::Notifications& GetVisibleNotifications() = 0;

    // Gets all notifications being shown as popups.  This should not be affected
    // by the change queue since notifications are not held up while the state is
    // VISIBILITY_TRANSIENT or VISIBILITY_SETTINGS.
    virtual NotificationList::PopupNotifications GetPopupNotifications() = 0;

    // Management of NotificationBlockers.
    virtual void AddNotificationBlocker(NotificationBlocker* blocker) = 0;
    virtual void RemoveNotificationBlocker(NotificationBlocker* blocker) = 0;

    // Basic operations of notification: add/remove/update.

    // Adds a new notification.
    virtual void AddNotification(scoped_ptr<Notification> notification) = 0;

    // Updates an existing notification with id = old_id and set its id to new_id.
    virtual void UpdateNotification(
        const std::string& old_id,
        scoped_ptr<Notification> new_notification)
        = 0;

    // Removes an existing notification.
    virtual void RemoveNotification(const std::string& id, bool by_user) = 0;
    virtual void RemoveAllNotifications(bool by_user) = 0;
    virtual void RemoveAllVisibleNotifications(bool by_user) = 0;

    // Sets the icon image. Icon appears at the top-left of the notification.
    virtual void SetNotificationIcon(const std::string& notification_id,
        const gfx::Image& image)
        = 0;

    // Sets the large image for the notifications of type == TYPE_IMAGE. Specified
    // image will appear below of the notification.
    virtual void SetNotificationImage(const std::string& notification_id,
        const gfx::Image& image)
        = 0;

    // Sets the image for the icon of the specific action button.
    virtual void SetNotificationButtonIcon(const std::string& notification_id,
        int button_index,
        const gfx::Image& image)
        = 0;

    // Operations happening especially from GUIs: click, disable, and settings.
    // Searches through the notifications and disables any that match the
    // extension id given.
    virtual void DisableNotificationsByNotifier(
        const NotifierId& notifier_id)
        = 0;

    // This should be called by UI classes when a notification is clicked to
    // trigger the notification's delegate callback and also update the message
    // center observers.
    virtual void ClickOnNotification(const std::string& id) = 0;

    // This should be called by UI classes when a notification button is clicked
    // to trigger the notification's delegate callback and also update the message
    // center observers.
    virtual void ClickOnNotificationButton(const std::string& id,
        int button_index)
        = 0;

    // Called by the UI classes when the settings buttons is clicked
    // to trigger the notification's delegate and update the message
    // center observers.
    virtual void ClickOnSettingsButton(const std::string& id) = 0;

    // This should be called by UI classes after a visible notification popup
    // closes, indicating that the notification has been shown to the user.
    // |mark_notification_as_read|, if false, will unset the read bit on a
    // notification, increasing the unread count of the center.
    virtual void MarkSinglePopupAsShown(const std::string& id,
        bool mark_notification_as_read)
        = 0;

    // This should be called by UI classes when a notification is first displayed
    // to the user, in order to decrement the unread_count for the tray, and to
    // notify observers that the notification is visible.
    virtual void DisplayedNotification(
        const std::string& id,
        const DisplaySource source)
        = 0;

    // Setter/getter of notifier settings provider. This will be a weak reference.
    // This should be set at the initialization process. The getter may return
    // NULL for tests.
    virtual void SetNotifierSettingsProvider(
        NotifierSettingsProvider* provider)
        = 0;
    virtual NotifierSettingsProvider* GetNotifierSettingsProvider() = 0;

    // This can be called to change the quiet mode state (without a timeout).
    virtual void SetQuietMode(bool in_quiet_mode) = 0;

    // Temporarily enables quiet mode for |expires_in| time.
    virtual void EnterQuietModeWithExpire(const base::TimeDelta& expires_in) = 0;

    // Informs the notification list whether the message center is visible.
    // This affects whether or not a message has been "read".
    virtual void SetVisibility(Visibility visible) = 0;

    // Allows querying the visibility of the center.
    virtual bool IsMessageCenterVisible() const = 0;

    // UI classes should call this when there is cause to leave popups visible for
    // longer than the default (for example, when the mouse hovers over a popup).
    virtual void PausePopupTimers() = 0;

    // UI classes should call this when the popup timers should restart (for
    // example, after the mouse leaves the popup.)
    virtual void RestartPopupTimers() = 0;

protected:
    friend class ::DownloadNotification;
    friend class ::DownloadNotificationTestBase;
    friend class MessageCenterImplTest;
    friend class MessageCenterImplTestWithChangeQueue;
    friend class MessageCenterImplTestWithoutChangeQueue;
    friend class MessageCenterTrayTest;
    friend class TrayViewControllerTest;
    friend class test::MessagePopupCollectionTest;
    virtual void DisableTimersForTest() = 0;
    virtual void EnableChangeQueueForTest(bool enabled) = 0;

    MessageCenter();
    virtual ~MessageCenter();

private:
    // Forces to flush the queued changes even when the message center opens. This
    // method is a workaround of UpdateNotification not updating notifications
    // while the message center.
    // Note carefully: this may break the layout of message center. Shouldn't use
    // this method if the update changes its notification size.
    virtual void ForceNotificationFlush(const std::string& id) { }

    DISALLOW_COPY_AND_ASSIGN(MessageCenter);
};

} // namespace message_center

#endif // UI_MESSAGE_CENTER_MESSAGE_CENTER_H_
